Work holding attachment for grinders



Dec. 23, 1958 M. SOAVE WORK HOLDING ATTACHMENT FOR GRINDERS Filed00%. 1. 1952 3 Sheets-Sheet l A? z INVENTOR.

ATTOPA/[F Dec. 23, 1958 M. SOAVE 2,865,149

WORK HOLDING ATTACHMENT FOR GRINDERS Filed Oct. 1, 1952 3 Sheets-Sheet 2INVENTOR. M4260 50/4 1 5 Dec. 23, 1958 M. SOAVE WORK HOLDING ATTACHMENTFOR GRINDERS Filed 001:. 1, 1952 3 Sheets-Sheet 5 INVENTOR.

MA/PCO 50,4 VA

70/P/VE7 United States Patent WORK HOLDING ATTACHMENT FQR GRENEEKS MarcoSuave, Hicksvilla N. Y.

Application October 1, 1952, Serial No. 312,527 3 Claims. (Cl. 51 -217This invention relates to improvements in work holders for grindingmachines.

More particularly, the invention is concerned with work holdingattachments for grinders of the type in which the work is ground againstthe fiat face of the grinding wheel, and a work support in the form of atiltable table is provided, permitting the work to be moved inparallelism with the grinding surface. In such machines, the worksupport is adjustable through a certain angle, to permit grinding at adesired angle with respect to the surface of the work support. In theusual machine of this type and used for miscellaneous grinding, as, forexample, in pattern shop work for the shaping of various pieces of'wocd,the work is held on the rest by hand and given the required traversemovement with respect to the wheel by hand. Adjustment to precise anglesis difiicult and the accident rate, due to fingers coming in contactwith the wheel, is high.

It is an object of the invention to provide an attachment for grindingmachines, permitting an extremely wide angle of adjustment, togetherwith ease and accuracy of adjustment beyond what can be obtained withthe conventional tilting work rest.

A second object of the invention is to provide a work support in whichthe work holding surface could be considerably shortened in thedirection at right angles to the grinding surface, permitting thegrasping of the work rearwardly at the edge of the Work supportingsurface and in a position where danger of dama'geto the fingers shouldthework slip is minimized.

Still another object of the invention is to provide a work holderattachment having a full range of adjustability and holding the work insuch a manner as to obviate any possibility of injury to the fingers,even when grinding small work pieces.

An attachment embodying the invention in a preferred form will now bedescribed with reference to the accompanying drawing, and the featuresforming the invention will then be pointed out in the appended claims.

In the drawing:

Figure 1 is a side elevation of the attachment, positioned on a grinder,indicated in phantom;

Figures 2 and 3 are side elevations on a large scale and showing theattachment in two different positions of adjustment;

Figure 4 is a plan View of the attachment, with parts broken way to showthe structure more clearly;

Figure 5 is a plan view of the attachment, removed from the machine andlaid flat;

Figures 6 and 7 are perspectives, showing a work holder used with theattachment of previous figures; and

ice

Figure 8 is a perspective showing the attachment with the work holderpositioned in a grinding machine, indicated in phantom.

In Figures 1 to 3 and 8, the grinding attachment of the invention isindicated in position in a grinder 1, having a grinding wheel 3, worksupport 5 and the usual slotted sectors 7 for pivotally supporting thework support, and the usual devices 9 for locking the work support inany desired adjusted position. The attachment includes a bed plate 11which seats on the work support 5 as indicated, with downwardly extendedflanges 13 which are fixed to the bed plate, abutting against therearward edge of the work support 5.

Upper boards or plates 15 and 17 hingedly connected together at 19 areprovided for-supporting the work, and may be adjusted to a variety ofpositions as hereinafter explained in detail. The forward edge of theplate 15 is provided with hooks 21, which engage under the work support5 on each side of the grinding wheel. The bar 21 passing through thehooks 21 and axially and slidably rotatable therein may be providedtogether with wing screws 21 for fixing it in desired position. This barhas its ends bent at an angle as shown, and may be utilized for locatingthe device widthwise of the grinder wheel. The elements 15 and 17 arefurther supported along their hinge line by a pair of supports 23, theupper "ends of which are hingedly coupled together at 25 and the lowerends of which are pivotally fixed to nuts 27 on the threadedshaft '29,which is journaled in the bedjpl'ate 11. The threading is right and lefthand, so that the lower ends of the elements 23 may be broughttogetheror spread apart for raising or lowering the point of support ofa hinge line between the boards -15 and 17..

Downwardly extending flanges 31 in the rearward edge of the board 17pivotally carry the slotted members 33 and35. The slot of the member 33receives a stud 37,-

and the member 33 may be locked in any desired position with relation tothe stud by a wing nut 39. The slotted link 35 receives a stud 41,similarly equipped with a wing nut 43. By adjusting these various parts,

the boards 15 and 17 may be positioned in a variety of positions, aslater described in more detail. Stops 45 are also provided forpositively locating the device. If the board 17 is rocked about theupper ends of the supports 23 in a counterclockwise direction, it'willbe apparentthat stops 45 will then come against the beveled rear edge ofthe member 11, thus limiting the forward movement of the member 17.

The board 15 may support the work W directly as indicated in Figure 1and may also support the work holder as shown in detail in Figures 6 to8. For this purpose, theboard 15 is equipped with a rack 47 along. eachof its side edges, andv a guide stud 49, and with a substantiallysemi-circular trough or support 51 carried by members 53 which haveslotted forwardly extending portions 55 engaged'under the stud 49 and inwhich there is journaled a shaft 57 to which are fixed pinio-ns '59forming'a parallel motion adjustment, by turning the handle 61 at oneend of the shaft 57. The trough 51 may thus be adjusted toward and awayfrom the grinding wheel along the board 15 as desired.

' The board '15 may be provided with lugs 15' having bars 15 as shown,to permit mounting 'of the member by bolting to any available members,if desired Thework holder of Figures 6 to 8 comprises a work supportplate 63, the forward edge of which rests on the board 15 and which maybe adjusted as will now be described. Legs 65 pivo-tally attached to around bar 67 which sits in the trough 51 are in turn pivotally attachedto the plate 63 by means of pins 69 passing through the upper ends ofthe arms 65 and also through bearings 71 attached to the plate 63.Elements 73 pivoted coaxially with the lower ends of the legs 65 carryrotatable poppet nuts 75, through which screws 77, turnable by means ofthe wing heads 79, pass. The screws 77 are restrained from movingaxially with reference to the upper ends of the legs 65 but are mountedfor rotatable swinging movement with reference thereto. A slotted sector81 cooperating with a wing nut 83 and stud fixed to the center leg 65permit locking the legs at a given angular position with reference tothe bar 67.

Four work clamps 85 are provided, their rearward ends being located bymeans of pins 87 received in sockets in the plate 63. Member 89 isprovided for each pair of clamps 85, the member 89 receiving a stud 91equipped with a wing nut 93. By backing off the wing nut 93, the clampsmay be released, lifting their forward ends and turning the wing nut 93will draw the clamps down to hold the work W securely against the plate63 as shown in Figure 8. By tightening wing nuts 79, the plate 63 may belocked together with its supporting structure so as to form a rigid, setsupport.

The attachment just described is capable of a great variety of uses,depending upon the work to be done and the grinding angle.

As will be apparent from Figures 1 and 2, the rest of the grinder itselfmay be set at a given angle and the attachment utilized in such a way asto position the work support board at a much higher angle, thus givingpractically any range. of adjustment desired. The angular adjustmentbeing by means of the crank 29 and operating on a toggle system, iseasily accomplished to an extremely high degree of accuracy.

The attachment may also be flattened out as indicated in Figure 3, theangle of the support board 15 to the grinding wheel being the same asthat of the surface of the machine rest 5. Any intermediate position ofadjustment is obviously available.

The usual machine rest 5 is of considerable width, as measuredperpendicularly to the grinding surface, so as to be capable ofsupporting relatively wide as well as narrow work pieces. Inconsequence, in grinding fairly short or narrow pieces, the operator iscompelled to hold them on the flat surface of the work rest and pressthem toward the grinding wheel, so that there is nothing to stop hishands from striking the grinding wheel should the work piece slip. Theboard 15 may be considerably narrower than the work rest, giving in theposition of Figure 1, an edge at the hinge line between boards 15 and17, against which the hands of the operator may stop should a workpiece, such as the piece W indicated in Figure 1, slip.

With the attachment of Figures 6 to 8, substantially complete protectionfor the hands is obtained, together with a delicate and exact controlover the grinding. The angle being set, it will not be disturbed byturning the handle 61 to advance the work holder toward the face of thegrinding wheel, nor will it be disturbed by a traversing movement of thework holder, which is maintained in parallelism by the bar 67 sliding inthe trough 51. The operator may thus give the required traversingmovement to the work by sliding the work holder back and forth with onehand, and feeding the work toward the grinder by turning handle 61 withthe other. Since the pressure of the hand will be exerted downwardlytoward the board 15 rather than toward the grinding wheel, there is nodanger of fingers being brought into contact with the grinding wheel.

The attachment of the invention is capable of use with a wide variety ofgrinding machines, including both disc and belt grinders and havingdifferent work table adjustments or no work table adjustment. Theadvantages will be apparent by considering its use with a grinder of thevery common type in which the Work table is adjustable between a rangeof approximately 10 above the horizontal for an open cut and 45 belowthe horizontal for a closed cut, or thereabouts.

Considering first the open cut, the attachment of the invention readilypermits grinding at an angle 68 above the horizontal (providing a bevelof 22), and, as above pointed out, provides accurate control andminimizes the possibility of injury to the fingers, while permittingoperation on pieces ranging from extremely small parts, too small to beheld by the hands, to large pieces of the approximate size of the worktable.

Even for open cuts at slight angles, and within the range of theexisting machine, the attachment of the invention has a marked advantagein that the work rest may be horizontal and solidly held by both bolts,whereas if the work table itself is placed at an angle, one of the bolts9 must be removed, so that the work table no longer furnishes a solidand firm support.

For closed cuts, the attachment of the invention permits increasing theangle from that provided by the work rest of the machine, or about 45,to about 70 or In this case, the wing nuts 39 and 43 are loosened, andthe attachment in fiat condition (Figure 3) is swung up, so that thefront edge of board 15 rests against the grinding wheel frame, and isthen fastened in place by tightening the nuts 39 and 43, the members 23supporting the hinge line.

In many cases, as where the part being ground is a flat board or metalplate, the edge may be ground at desired angle by either an open cut ora closed cut. In other cases, however, as where the two faces of theWork piece are not flat, or where the ground surface must be accuratelyrelated to one of the surfaces, it is not possible to select as betweenopen and closed cutting, and in his case, it will be apparent that theattachment of the invention enormously increases the capacity of themachine, permitting a full range of operation with wood and metal partsof practically any size and shape.

What is claimed is:

1. A work supporting attachment for grinding wheels,

comprising a support board adapted to fit on the work rest of a grinder,a pair of boards hinged together, means for adjustably supporting thesaid pair of boards on the support board, at a selected position in arange betweena position where the pair of boards lie flat on the supportboard and a position with the hinge line at a predetermined elevationfrom the support board and each of the pair of boards slantingdownwardly toward the support board therefrom, and a trough for slidablysupporting a work holder and a parallel motion supporting the trough onone of the boards parallel to the hinge line for move-- ment toward andaway from the hinge line.

2. An attachment according to claim 1, in which the parallel motioncomprises a rotatable shaft, a pinion fixed to each end of the shaft anda cooperating rack for each pinion mounted on the support board.

3. A work holding attachment for grinding machines, comprising a board,means for attaching the board to the work rest of a grinding machine, atrough, means mounting the trough on the board and including a parallelmotion for adjusting its distance from an edge thereof, a work holdercomprising a work support plate and means for clamping a piece of workthereto, and means for sup porting the work support plate at an angle tothe said board and with one edge resting thereon, the last said.

means including a bar in the trough and slidable therealong, whereby thework holder is slidable for traversing a work piece held therein, legssupporting the oppo site edge of the plate from the bar and pivotallyconnected to the plate, and means for adjusting the angle of ReferencesCited in the file of this patent UNITED STATES PATENTS Daniels May 29,1855 Klaber Oct. 6, 1874 Sargent Mar. 20, 1883 Strehl Feb. 26, 1907 10Strehl Dec. 5, 1922 McCollough Feb. 5, 1924 6 Gaimpeter Feb. 14, 1928Markaroff Sept. 1, 1936 Amendola Aug. 21, 1951 FOREIGN PATENTS GreatBritain July 8, 1913 Denmark June 21, 1923 Sweden Nov. 23, 1948 FranceJuly 10, 1928 France Sept. 16, 1935

